Consistent decrease in conifer embolism resistance from the stem apex to base resulting from axial trends in tracheid and pit traits.

Introduction: Drought-induced embolism formation in conifers is associated with several tracheid and pit traits, which vary in parallel from stem apex to base. We tested whether this axial anatomical variability is associated with a progressive variation in embolism vulnerability along the stem from apex to base.

Methods: We assessed the tracheid hydraulic diameter (), mean pit membrane area () and the xylem pressure at 50% loss of conductivity () on longitudinal stem segments extracted at different distances from the stem apex () in a and an tree.

No xylem phenotypic plasticity in mature Picea abies and Fagus sylvatica trees after 5 years of throughfall precipitation exclusion.

Forest trees are experiencing increasing frequency and intensity of drought events with climate change. We investigated xylem and phloem traits from mature Fagus sylvatica and Picea abies trees after 5 years of complete exclusion of throughfall precipitation during the growing season. Xylem and phloem anatomy, leaf and branch biomass were analysed along top branches of ~1.

Susceptibility to and functional xylem anatomy in : revisiting a tale of plant-pathogen interaction.

is a xylem-limited bacterium causing the Olive Quick Decline Syndrome, which is currently devastating the agricultural landscape of Southern Italy. The bacterium is injected into the xylem vessels of leaf petioles after the penetration of the insect vector's stylet. From here, it is supposed to colonize the xylem vasculature moving against water flow inside conductive vessels.